Aimed at ex-situ toughening technology and Z-direction RTM process,Darcy''s law was modified by introducing the saturation parameter.The partial differential equation describing the unsteady flow of the resin in the fiber preform was established.The effect of process parameters such as volume flow rate, resin viscosity and fiber preform''s permeability during the constant flow process on the injection pressure was investigated.The resin flow between intra-tow and inter-tow of the preform with untoughened layers and toughened layers was simulated.The results show that the numerical simulation results are reliable.The inner pressure in the fiber performs increases with the increase of injection time.The injection pressure increases linearly with the increase of volume flow rate and resin viscosity, while decreases with the increase of fiber preform''s permeability, which accords with Darcy''s law.The infiltration visualization of resin flow through meso-scale and micro-scale fiber preform is realized, which provides an important supplement for prediction of the macro-flow in fiber preforms and provides guidance for actual process.%针对"离位"增韧技术和Z-RTM成型技术,引入饱和度参数修正Darcy定律,建立描述树脂在纤维预制件中非稳态流动的偏微分方程,研究恒流注射过程中体积流量、树脂黏度和纤维预制件渗透率等工艺参数对非稳态浸润过程注入压力的影响,模拟树脂在层间未增韧和增韧纤维预制件束内和束间的流动.结果表明:数值模拟结果具有可靠性;随着注射时间的增加,纤维预制件内部各点的压力增加;随着体积流量、树脂黏度的增加,注入压力线性增加,而随着纤维渗透率的增加,注入压力减少,符合Darcy定律;实现了树脂在纤维预制件细微观层次浸润的可视化,这种可视化结果为预测树脂在预制件中的宏观流动提供了重要补充,并为实际工艺提供了一定指导作用.
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